U.S. Measles Cases, Outbreaks Quadruple in 2011

April 19, 2012 -- Measles cases are spiking sharply in the U.S., the CDC reported today.

The 222 cases and 17 outbreaks seen in 2011 are nearly four times the median of 60 cases and four outbreaks per year seen over the last decade. A third of patients were hospitalized.

The surge in cases is largely due to people who have not been vaccinated with the measles/mumps/rubella (MMR) vaccine, the CDC says. A significant percentage of these people are children and teens whose parents exempted them from school vaccination requirements.

"Unvaccinated people put themselves and others at risk -- particularly infants too young to be vaccinated, who can have the most severe complications," Anne Schuchat, MD, director of the CDC's National Center for Immunization and Respiratory Diseases, said at a news conference held to announce the new report.

Measles Makes European Comeback

Vaccine refusal is more common in Europe than in the U.S. The result: more than 37,000 measles cases in Europe last year. Five countries account for 90% of the cases: France, Italy, Romania, Spain, and Germany.

Nine out of 10 U.S. measles cases could be linked either to a U.S. resident who was infected in a foreign country or to foreign visitors to the U.S. Many of these travelers imported measles from Europe.

Thanks to high vaccination rates in the 1990s, the U.S. eliminated year-round measles transmission in 2000. But the current spike in cases threatens that achievement.

Schuchat pointed to France, which was down to about 40 measles cases per year. Suddenly that went to 604 cases in 2008, over 5,000 cases in 2010, and over 15,000 cases in 2011.

"You can go from a small number to a very large number of measles cases very quickly," Schuchat warned.

Fortunately there were no measles deaths in the U.S. in 2011, although one infant in intensive care had a narrow brush with death. Before the measles vaccine came along in 1957, there were one to three deaths for every 1,000 cases. Worldwide, measles kills 164,000 people a year.

While U.S. measles vaccination rates remain high, pockets of unvaccinated children offer a foothold to the virus. And that's all this extremely contagious, airborne disease needs.

"You can catch measles just by being in a room in which an infected person has been, even if that person has left the room," Schuchat said. "And you can get it from another person before that person has symptoms."

It's too soon to tell whether measles cases will continue to spike in 2012. So far there have been 27 cases and two outbreaks.

If you're thinking of traveling this summer -- to the London Olympics, for example -- now is the time to get vaccinated.

"Bring back memories, not measles," Schuchat says.

The report appears in the April 20 issue of the Morbidity and Mortality Weekly Report.